Computed Tomography Department, Heart Institute (InCor), University of Sao Paulo Medical School, Brazil.
Clinical Cardiology - Geriatric Cardiology, Heart Institute (InCor), University of Sao Paulo Medical School, Brazil.
J Cardiovasc Comput Tomogr. 2018 Jul-Aug;12(4):312-315. doi: 10.1016/j.jcct.2018.03.009. Epub 2018 Apr 5.
The importance of bolus tracking (BT) regarding total effective radiation dose (ERD) in the era of advanced coronary computed tomography angiography (CTA) has been ignored. We aimed to investigate whether adjusting BT parameters reduces ERD.
Adults consecutively referred to CTA (n = 289) in a 320 detector-row scanner were distributed into four BT protocols according to delay time and time between intermittent scans, as follows: A (n = 70, delay 10s, intermittent scans 1s); B (n = 79, delay 10s, intermittent scans 2s); C (n = 68, delay 15s, intermittent scans 1s); and D (n = 72, delay 15s, intermittent scans 2s). Image quality was assessed.
The overall ERD in BT and AP were 0.32 ± 0.14 mSv and 6.06 ± 0.66 mSv, respectively. ERD in BT was different among protocols (A:0.44 ± 0.14 mSv; B:0.32 ± 0.10 mSv; C:0.28 ± 0.14 mSv; D:0.23 ± 0.09 mSv; p < 0.001), with no loss in image quality. Adjusted for potential confounders (heart rate, tube current and acquisition window), protocol D provided the highest reduction in total ERD (β = -0.33, p = 0.004).
Delaying initiation of BT images (and acquiring them less frequently) reduces radiation dose and does not impair image quality.
在先进的冠状动脉计算机断层扫描血管造影（CTA）时代，团注追踪（BT）对总有效辐射剂量（ERD）的重要性被忽视了。我们旨在研究调整 BT 参数是否可以降低 ERD。
在 320 排探测器 CT 扫描仪中，连续对 289 例成人进行 CTA（n=289）检查，根据延迟时间和间歇扫描时间，将其分为四个 BT 方案：A（n=70，延迟 10s，间歇扫描 1s）；B（n=79，延迟 10s，间歇扫描 2s）；C（n=68，延迟 15s，间歇扫描 1s）；D（n=72，延迟 15s，间歇扫描 2s）。评估图像质量。
BT 和 AP 的总 ERD 分别为 0.32±0.14mSv 和 6.06±0.66mSv。BT 方案之间的 ERD 不同（A：0.44±0.14mSv；B：0.32±0.10mSv；C：0.28±0.14mSv；D：0.23±0.09mSv；p<0.001），但图像质量没有损失。调整潜在混杂因素（心率、管电流和采集窗）后，方案 D 提供了总 ERD 最高的降低（β=−0.33，p=0.004）。
延迟 BT 图像的启动（并减少其采集频率）可以降低辐射剂量，而不会损害图像质量。
